Multiple System Operators (MSOs) and other service providers operate or provide networks, for example, using Data-Over-Cable Service Interface Specifications (DOCSIS). DOCSIS describes the operation of a data network over a cable network such as a hybrid fiber-coaxial (HFC) cable network.
DOCSIS Set-Top Gateway (DSG) is a specification that allows cable headend equipment, such as a Cable Modem Termination System (CMTS), to provide out-of-band (OOB) messaging in a DOCSIS network. DSG can be used to send OOB messaging over existing cable networks to customer premises equipment (CPE), such as set-top boxes (STBs), media gateways (MGs), and other devices such as cable modems (CMs) that are able to receive signals from a CMTS. Alternatively, the information can be sent over other broadband access network topologies, such as Fiber To The Home (FTTH).
DSG can typically be implemented in pre-existing DOCSIS network infrastructure without requiring significant changes to the DOCSIS network infrastructure. However, the interface and protocol defined by DSG introduce additional requirements on the DOCSIS CMTS and DOCSIS cable modems (CMs), in order to support the configuration and transport of OOB messaging between a headend device and the CPE.
DSG is described, for example, in a specification that has been made publicly available: Cable Television Laboratories, Inc., Data-Over-Cable Service Interface Specifications: DOCSIS Set-top Gateway (DSG) Interface Specification, CM-SP-DSG-I24-130808 (August 2013).